A circuit breaker is described in German Patent No. 44 16 105. In this circuit breaker, screws extending through openings made transversally to the longitudinal axis of the connecting bars are used as the fastening means for the connecting bars, with corresponding female threads provided in the rear wall of the enclosure to accommodate these screws. Since the rear wall of the enclosure is a molded body made of insulating material, usually insert nuts or pressed-in nuts are used for providing the female thread.
In circuit breakers of this type, for high-intensity current that may range between 1000 A and 6000 A, the connecting bars have a considerable cross section. Accordingly, the connecting bars are provided with a plurality of cross bores as needed and a corresponding number of fastener means is required. Therefore, a non-negligible cost for machining the connecting bars is incurred to incorporate connecting bars in such a circuit breaker.
The present invention differs from a circuit breaker described in U.S. Pat. No. 3,287,534, whose main circuit path, in addition to internal main conductors, has external connecting bars detachably connected to the main conductors. These connecting bars have webs extending transversally in their longitudinal direction, which are not used for positioning the main current path as a whole and supporting it in the circuit breaker enclosure. Rather, the webs, designed as rectangular flanges with fastening orifices, provide the user with the option of mounting the connecting bar in two positions 90.degree. apart to match the different possible positions of the downstream connecting bars in a switching system. This arrangement requires separate fastening of the internal main conductor, designed as the support of a stationary switching contact and of an articulated conductor arrangement, in the circuit breaker enclosure. The connecting bars are in turn connected to the main conductors using additional fastening elements. In order to allow the connecting bars to be mounted in a different position, the internal main conductors have a clamping surface, accessible via a window in the rear wall of the circuit breaker enclosure. Thus, in order to make the circuit breaker variably connectable, no effort was made to seek a method of mounting the main current path using the fewest possible fastening elements and the fewest possible machining steps for the components of the main current path.